Self-priming lateral channel centrifugal pump

ABSTRACT

A self-priming lateral channel centrifugal pump having a pair of ribs formed in the suction chamber to enhance the self-priming features of the pump. The fluid traverses a substantial portion of the suction chamber before porting to the impeller, and the ribs are located just in advance of the impeller port. One of the ribs extends radially inwardly of the suction chamber and the other radially outwardly from the inner region of the chamber. The ribs are circumferentially spaced and both extend the entire axial width of the suction chamber and about half the radial depth of the chamber.

United States Patent Hagemann 1 Mar. 14, 1972 [54] SELF-PRIMING LATERALCHANNEL [56] References Cited CENTRIFUGAL PUMP UNITED STATES PATENTS 1 1lnvemofl Wall" 8 ltzehoe-Nordoe- 1,269,063 6/1918 De Laval ..415/183 iGermany 3,462,949 8/1969 Anderson et al ....415/1s3 2,051,080 8/1936Frederick i ..415/53 [73] Assgnee 2 meme Hdmm 3,252,421 5/1966 Luhmann..4|s/1s2 ermany [22] Filed: July 2, 1970 Primary Examiner-Henry F.Raduazo Attorney-Oberlin, Maky, Donnelly & Renner [21] Appl. No.: 51,918

[ ABSTRACT [30] Foreign Application Priority Data A self-priming lateralchannel centrifugal pump having a pair of ribs formed in the suctionchamber to enhance the self July 5, Germany ..P p g features of the Thetraverses a substantial portion of the suction chamber before porting tothe impeller, [52] US. Cl AIS/182, 415/213 T and the ribs are located ji advance f the impeller port. [51] Int. Cl ..F04d 29/40, F04d 1/00 Oneof the ribs extends radially inwardly of the suction [58] Field ofSearch ..4l5/53 T, 213 T, 217, 182, chamber and the other radiallyoutwardly from the inner re- 415/183, 184, 185 gion of the chamber. Theribs are circumferentially spaced and both extend the entire axial widthof the suction chamber and about half the radial depth of the chamber.

5 Claims, 4 Drawing Figures Patented March 14, 1972 3,649,131

2 Sheets-Sheet 1' T F; Fig.1

Patented March 14, 1972 3,649,131

2 SheetS-Sheet 2 SELF-PRIMING LATERAL CHANNEL CENTRIFUGAL PUMP Theinvention a self-priming lateral channel centrifugal pump withhorizontal shaft, a pump inlet situated on the underside and pointingdownwards, an annular suction chamber, a port from the suction chamberto the pumping area of the pump, situated to the side of the impellerand on a level with or lower than the shaft and with a dividing wall inthe suction chamber, placed between the pump inlet and the port to thepumping area.

The pump covered by the invention is primarily for application in tankswith a dispenser pump for the pumping of automotive fuels, where thesehave to be pumped up from underground containers. For reasons of priceand space, a simple pump design with a fitting that is uncomplicated andthat does not take up too much room is necessary. A simple pipe systemworking at low deformation with as few connections in the pump system aspossible is desirable in order to reduce leakage losses of the pumpingsubstance in the dispensing pump.

A further important point is that the pump must be selfpriming withoutthe use of additional auxiliary pumps (e.g., hand pump), valves ornonreturn flaps even for the pumping of fuels that easily gasify; thismeans that the pump must at any time suck up the gases or vapor of thepumping substance in the pump and the connected pipes after the pump hasbeen filled once, even after considerable periods of shutdown, commencepumping the fluid after the gas has been sucked up and be in a positionto pump fluid containing gas without difficulty or interruption.

The aim was to construct a simple design for a self-priming lateralchannel centrifugal pump with horizontal shaft, and with a pump inletsituated on the underside and pointing downwards, so that this inlet canbe flanged directly onto the intake line leading down to the undergroundcontainer without the insertion of the pipe bends or other pipefittings. This positioning of the pump inlet means, however, that afterswitching the pump off, the greater proportion of the fluid contained inthe pump casing flows back into the tank and is thus no longer availablefor further priming of the pump; this means that special measures arenecessary to achieve the ability to self-prime.

A self-priming lateral channel centrifugal pump is known in that formthat the pump inlet is situated, as is usual, on the top side which doesnot enable a simple intake line from an underground container to thepump inlet, but requires, for example, two quarter bends in the intakeline. The positioning of the pump inlet on the top side makes itpossible that, after the pump has been switched off and the transportfluid falls back into the tank, a sufficient quantity of fluid remainsin the pump.

Other pumps are known in that form that normal operation is guaranteedby nonreturn flaps installed in the pump, which prevent the absence offluid in the pump after switching off.

The solution of the named disadvantages according to the invention isthat the pump inlet situated on the underside of the pump leads straightinto the suction chamber and that in the inflow direction two ribs arefitted in the suction chamber a short distance before the port; one ribis fitted inthe inner radial area, the other in the outer radial area ofthe suction chamber. Both ribs cover the entire axial width and abouthalf the radial cross section of the suction chamber.

This positioning of the pump inlet facilitates a feed system with littledeformation and with few joints that is easily installable; the placingof the two ribs in front of the port enables good self-priming withoutthe use of nonreturn flaps, valves or similar devices in spite of thefact that the pump inlet points downwards.

Tests have shown that the presence of both ribs is necessary in order toensure self-priming. The effect of the ribs placed in the suctionchamber is that the operational fluid spun out of the channel into thesuction chamber by the impeller during the removal of air from thesystem is collected and fed back to the pumping area through'theport.The rib situated in the inner radial area of the suction chamber alsoinfluences the level of fluid in the suction chamber and, together withthe rib situated in the outer radial area of the suction chamber,prevents the operational fluid frombeing lost to the suction intake.

According to a further characteristic of the invention, it is useful forthe ribs situated in the inner radial area of the suction chamber to beplaced first in the direction of flow and for the rib situated in theouter radial area of the suction chamber to follow since a part of theoperational fluid supply that is spun out of the port into the suctionchamber by the impeller during the removal of air from the systemis-caught directly by the outer radial rib and fed back to the pumpingarea through the port.

According to a further characteristic of the invention, it is usefulthat both ribs in front of the port be inclined towards this and/or bebent at their radial free end towards the port since the ribs feed theoperational fluid that is spun out during the removal of air from thesystem back to the port and the pumping area as described above,whereas, on the other hand, in normal fluid pumping where the fluidflows from the pump inlet to the port the ribs are. shaped to furtherflow; this also effects a favorable flow of the impeller segments, sothat a better Ah value is provided by the ribs than is to be found in apump without ribs.

It has also proved advantageous for the direction of rotation of theimpeller to be opposed to the direction of flow in the annular shapedsuction chamber, since the port from the pumping area to the pressurechamber of the pump is then situated in the lower part of the pump. Thisproves to be favorable during removal of air from the system, since nooperational fluid that reaches the pressure chamber together with thegas is lost.

In order to simplify the structural design of the pumping section, whichcomprises the pump inlet, the suction chamber and the ribs, theinvention proposes that the lateral channel be situated on that side ofthe impeller away from the port leading from the suction chamber to thepumping area.

The preferred forms of the invention are illustrated in the accompanyingdrawings, in which:

FIG. shows an overall view,

FIG. 2 and FIG. 3 each show an interior view of the suction chamber ofthe pump on the Section A-B as in FIG. 1.

FIG. 4 is a section through the casing of the pump on the Section CD inFIG. 3. The arrows with solid lines show the route of the pumpingmaterial.

The self-priming lateral channel centrifugal pump 1 in FIG. 1 is in thisinstance equipped with an elastic motor 2 and shows the pump inlet 3situated on the underside.

FIG. 2 shows the part of the casing 4 containing the pump inlet 3 withhorizontal shaft 5, annular suction chamber 6 and the port 8 situated tothe side of the impeller 7. The shorter, direct route of the pumpingmedium from the pump inlet to the port is barred by a dividing wall 9 inthe annular suction chamber, so that the flow has to pass the ribs 10and 11 situated in front of the port.

FIG. 3 shows another version of the invention with the same key numbersfor the pump components as in FIG. 2. The pump inlet 3 and the ribs 10and 11 are situated differently in comparison with FIG. 2 and the arrowwith a broken line on the impeller 7 shows its direction of rotation ifthis is opposed to the direction of flow in the annular suction chamber.

FIG. 4 is a cross section on the line CD in FIG. 3 through the pumpcasing showing the rib ll partially in section, the rib l0 and thedividing wall 9 in elevation.

The port 13 from the lateral channel 12 to the pressure chamber of thepump is situated in the lower part of the pump, the lateral channel 12is situated on that side of the casing 4 away from the impeller 7, whilethe dividing wall 9 and the ribs 10 and 11 are sealed off laterally bythe casing wall 14.

The invention is not restricted to the pumps for tank systems describedabove. It can be applied in any circumstances where similar requirementshave to be met in respect of the arrangement of the pump inlet and ofsaving space in self-priming pumps.

We claim:

I. A self-priming lateral channel centrifugal pump comprising ahorizontal shaft, an impeller mounted on said shaft for rotationtherewith, and an intake casing having an annular suction chamber, saidcasing having a wall separating said chamber from said impeller, a portformed in said wall for directing fluid from said suction chamber tosaid impeller, said port extending below the level of said shaft, a pumpinlet provided in the lower part of said suction chamber, a dividingwall extending transversely in said suctionchamber below said port forpreventing fluid entering said inlet from flowing directly to said port,a pair of ribs formed in said suction chamber slightly in advance ofsaid port in the direction of travel of the fluid, one of said ribsextending radially inwardly from the radially outer region of saidsuction chamber and the other of said ribs extending radially outwardlyfrom the radially inner region of said chamber, both of said ribsextending the entire axial width of said suction chamber and about halfthe radial depth of said chamber.

2. The pump of claim 1 wherein said other rib situated in the innerradial region of said suction chamber is placed first in the directionof flow and said rib situated in the outer radial region of said suctionchamber follows.

3. The pump of claim 1 wherein both of said ribs are inclined at theirradial free ends towards said port.

4. The pump of claim 1 wherein the direction of rotation of saidimpeller is opposed to the direction of fluid flow in said suctionchamber.

5. The pump of claim 1 wherein said lateral channel is situated on thatside of the impeller away from the port leading from said suctionchamber to the pumping area.

1. A self-priming lateral channel centrifugal pump comprising ahorizontal shaft, an impeller mounted on said shaft for rotationtherewith, and an intake casing having an annular suction chamber, saidcasing having a wall separating said chamber from said impeller, a portformed in said wall for directing fluid from said suction chamber tosaid impeller, said port extending below the level of said shaft, a pumpinlet provided in the lower part of said suction chamber, a dividingwall extending transversely in said suction chamber below said port forpreventing fluid entering said inlet from flowing directly to said port,a pair of ribs formed in said suction chamber slightly in advance ofsaid port in the direction of travel of the fluid, one of said ribsextending radially inwardly from the radially outer region of saidsuction chamber and the other of said ribs extending radially outwardlyfrom the radially inner region of said chamber, both of said ribsextending the entire axial width of said suction chamber and about halfthe radial depth of said chamber.
 2. The pump of claim 1 wherein saidother rib situated in the inner radial region of said suction chamber isplaced first in the direction of flow and said rib situated in the outerradial region of said suction chamber follows.
 3. The pump of claim 1wherein both of said ribs are inclined at their radial free ends towardssaid port.
 4. The pump of claim 1 wherein the direction of rotation ofsaid impeller is opposed to the direction of fluid flow in said suctionchamber.
 5. The pump of claim 1 wherein said lateral channel is situatedon that side of the impeller away from the port leading from saidsuction chamber to the pumping area.